pdp11v/usr/man/a_man/man1/getty.1m

.TH GETTY 1M
.SH NAME
getty  \- set terminal type, modes, speed, and line discipline
.SH SYNOPSIS
.B /etc/getty
[
.B \-h
] [
.B \-t
timeout
]
line
[
speed
[
type
[
linedisc
] ] ]
.br
.B /etc/getty \-c
file
.SH DESCRIPTION
.I Getty
is a program that is invoked by
.IR init (1M).
It is the second process in the series,
.RI ( init-getty-login-shell )
that ultimately connects a user with the \s-1UNIX\s0 System.
Initially
.I getty
prints the login message field for the entry it is using from
.BR /etc/gettydefs .
.I Getty
reads the user's login name and invokes the
.IR login (1)
command
with the user's name as argument.
While reading the name,
.I getty
attempts to adapt the system to the speed and type of terminal
being used.
.PP
.I Line
is the name of a tty line in \f3/dev\fP to which
.I getty
is to attach itself.
.I Getty
uses this string as the name of a file in the \f3/dev\fP directory
to open for reading and writing.
Unless
.I getty
is invoked with the
.B \-h
flag,
.I getty
will force a hangup on the line by setting the speed to zero
before setting the speed to the default or specified speed.
The
.B \-t
flag plus \fItimeout\fP in seconds, specifies that
.I getty
should exit if the open on the line succeeds and no
one types anything in the specified number of seconds.
The optional second argument,
.IR speed ,
is a label to a speed and tty definition in the file
.BR /etc/gettydefs .
This definition tells
.I getty
what speed to initially run at, what the login message should look
like, what the inital tty settings are, and what speed to try next
should the user indicate that the speed is inappropriate. (By typing a
.I <break>
character.)
The default \fIspeed\fP is 300 baud.
The optional third argument,
.IR type ,
is a character string describing to
.I getty
what type of terminal is
connected to the line in question.
.I Getty
understands the following types:
.P
.RS
.nf
\f3none\f1		default
\f3vt61\f1		\s-1DEC\s+1 vt61
\f3vt100\f1		\s-1DEC\s+1 vt100
\f3hp45\f1		Hewlett-Packard \s-1HP\s+145
\f3c100\f1		Concept 100
.fi
.RE
.P
The default terminal is \f3none\fPp; i.e.,
any crt or normal terminal unknown to the system.
Also, for terminal type to have any meaning, the virtual
terminal handlers must be compiled into the operating system.
They are available, but not compiled in the default condition.
The optional fourth argument,
.IR linedisc ,
is a character string describing which line discipline to use
in communicating with the terminal.
Again the hooks for line disciplines are available in the
operating system but there is only one presently available,
the default line discipline,
.SM
.BR LDISC0\*S .
.PP
When given no optional arguments,
.I getty
sets the \fIspeed\fP of the interface to 300 baud,
specifies that raw mode is to be used (awaken on every character),
that echo is to be suppressed, 
either parity allowed,
newline characters will be converted to carriage return-line feed,
and tab expansion performed on the standard output.
It types the login message before reading
the user's name a character at a time.
If a null character (or framing error) 
is received, it is assumed to be the result
of the user pushing the ``break'' key.
This will cause
.I getty
to attempt the next \fIspeed\fP in the series.
The series that
.I getty
tries is determined by what it finds in
.BR /etc/gettydefs .
.PP
The user's name is terminated by a new-line or
carriage-return character.
The latter results in the system being set to
treat carriage returns appropriately (see
.IR ioctl (2)).
.PP
The user's name is scanned to see if
it contains any lower-case alphabetic characters; if not,
and if the name is non-empty, the
system is told to map any future upper-case characters
into the corresponding lower-case characters.
.PP
Finally,
.I login
is called with the user's name as an argument.
Additional arguments may be typed after the login name.  These are
passed to
.IR login ,
which will place them in the environment (see
.IR login (1)).
.PP
A check option is provided.  When
.I getty
is invoked with the
.B \-c
option and \fIfile\fP, it scans the file as if it were scanning
.B /etc/gettydefs
and prints out the results to the standard output.  If there
are any unrecognized modes or improperly constructed entries, it
reports these.  If the entries are correct, it prints out the
values of the various flags.  See
.IR ioctl (2)
to interpret the
values.  Note that some values are added to the flags automatically.
.SH FILES
/etc/gettydefs
.SH "SEE ALSO"
ct(1C),
init(1M),
login(1),
ioctl(2),
gettydefs(4),
inittab(4),
tty(7).
.\"	@(#)getty.1m	5.2 of 5/18/82